Del Tacca M, Bernardini M C, Corsano E, Martinotti E, Rozé C
Institute of Medical Pharmacology, University of Pisa, Italy.
Arch Int Pharmacodyn Ther. 1989 Jan-Feb;297:178-89.
The relationship between a wide range of doses of i.p. morphine and the effects of gastric secretion in several rat experimental models was investigated. In unoperated rats, morphine 5-15 mg/kg dose-dependently decreased gastric acidity, but an excitatory effect was observed with 0.5-1.5 mg/kg. A dose-dependent inhibition was also obtained in conscious pylorus-ligated rats with morphine 5-15 mg/kg, whereas no significant effects were found at lower doses. By contrast, acid concentration was enhanced with morphine 0.5-15 mg/kg in anaesthetized pylorus-ligated rats and in stomach lumen perfused rats. The changes of pepsin concentration correlated with the changes in gastric secretory volume. An increase in the volume was associated with a decrease in pepsin concentration, while pepsin amount per stomach was dose-dependently increased in all the conditions under which morphine increased gastric acidity. All the effects of morphine on acid and pepsin secretion were prevented by naloxone 1 mg/kg i.p. Overall results indicate that morphine may induce both excitatory and inhibitory effects on gastric secretion in the rat: these effects depend on the dose of morphine and the experimental conditions.
研究了腹腔注射多种剂量吗啡与几种大鼠实验模型中胃分泌效应之间的关系。在未手术的大鼠中，5 - 15mg/kg剂量的吗啡可剂量依赖性地降低胃酸度，但0.5 - 1.5mg/kg剂量时观察到兴奋作用。在清醒的幽门结扎大鼠中，5 - 15mg/kg剂量的吗啡也可产生剂量依赖性抑制，而较低剂量时未发现显著影响。相比之下，在麻醉的幽门结扎大鼠和胃腔灌注大鼠中，0.5 - 15mg/kg剂量的吗啡可提高胃酸浓度。胃蛋白酶浓度的变化与胃分泌量的变化相关。分泌量增加与胃蛋白酶浓度降低相关，而在吗啡增加胃酸度的所有情况下，每只胃中胃蛋白酶的量呈剂量依赖性增加。腹腔注射1mg/kg纳洛酮可阻止吗啡对胃酸和胃蛋白酶分泌的所有作用。总体结果表明，吗啡可能对大鼠胃分泌产生兴奋和抑制作用：这些作用取决于吗啡的剂量和实验条件。
